While the presence of high concentrations of opiate receptors and endogenous opioid peptides has been reported in the amygdala, the apparent absence of involvement of this system in the immediate perception of pain has left opioid peptide function within the amygdala a matter for speculation. However, experiments recently completed in our laboratory have indicated that manipulation of opiate activity within the amygdala of rats alters time-dependent memory processes. Therefore, our proposed research has been designed to provide a detailed pharmacological and neuroanatomical analysis of the effects of opiates and endogenous opioid peptides administered into the amygdala complex on learning and memory processes. To this end we have chosen to initially investigate the effects of opiate and opioid peptide administration on (1) acquisition of heart-rate conditioning, and (2) retention of heart rate conditioning in the New Zealand rabbit. In addition, an attempt will be made in this research to determine whether opiate activity within the amygdala alters learning and memory processes by interaction with the norepinephrine system within the amygdala. The results of this research should (1) provide important information regarding the normal function of the amygdala opioid peptide system, (2) elucidate critical neuroanatomical and neurochemical systems within the amygdala which participate in time-dependent memory processes, and (3) may reveal a mechanism by which opiate and opioid activity within the amygdala alters learning and memory processes.